import math
class vector:
    def __init__(self,x,y):
        self.pos = [x,y]
    def change(self,vec):
        self.pos[0] = vec.get()[0]
        self.pos[1] = vec.get()[1]
    def get(self):
        return (self.pos[0],self.pos[1])
    def add(self,vec):
        self.pos[0] = self.pos[0]+vec.get()[0]
        self.pos[1] = self.pos[1]+vec.get()[1]
    def sub(self,vec):
        self.pos[0] = self.pos[0]-vec.get()[0]
        self.pos[1] = self.pos[1]-vec.get()[1]
    def length(self):
        return math.sqrt(self.pos[0]**2+self.pos[1]**2)
    def normalized(self):
        return(math.sqrt(self.pos[0]**2)/abs(self.length()),math.sqrt(self.pos[1]**2)/abs(self.length()))
